osx: make zip contain symlinks now. Surprisingly trying to use a 'copy' of a
     dylib will crash python. if its a symlink then its all good.
     also, spawn even in the bg so as not to block.
Merge pull request #1186 from monkeyiq/2014feb/ipythonupdates6

osx: make zip contain symlinks now. Surprisingly trying to use a 'copy' ...